1. Field of the Invention:
This invention relates to a method of recording on a magnetic tape attached to a card in which an audio signal of an analog quantity to be recorded is first PCM converted and stored in a solid memory in a pulse form and then this pulse coded signal is read at high speed, again converted into an analog audio signal and dubbed at high speed to the slave tapes by a plural number of tape recorders.
2. Description of the Prior Art:
There is known an audiovisual teaching machine, or so-called "card recorder", in which a magnetic tape having recorded thereon the commentary voices is attached to each card carrying a picture, letter, character, etc., and such magnetic tape is run in contact with the reproducing head of a tape recorder so that the student can learn a language by seeing the picture, letter, etc., while hearing the voice explaining such picture, letter, etc. The cards having attached thereto said magnetic tapes and carrying the same contents of expression are prepared in plurality, and hence there are accordingly required a plurality of magnetic tapes having the same recording contents. Heretofore, a plural number of endless tapes carrying the recorded voices of the same contents have been run continuously so as to reproduce the voices at a period of about 10 seconds and the reproducing outputs thereof have been recorded continuously and at high speed by a single or plural tapes. According to such conventional practice, however, since each endless tape with a length of approximately one meter is run repetitively for reproduction, there would inevitably take place the deterioration of sound quality due to wear of the tape or deposition of dust and variation of the reproducing output level due to dust deposition and other causes as well as wear of the magnetic head and other mechanical parts in use, so that constant watch and other troublesome works were required for maintaining the quality of the magnetic tape and timbre of the reproduced sound. Also, such endless tape was subject to a certain limitation in high speed dubbing for the mechanical reasons of the tape recorder.